#include <iostream>
#include <string>
using namespace::std;
int* prefix(string str);
int firstent(string str, string pattern);
int main()
{
	string T, P;
	getline(cin, T);
	getline(cin, P);
	cout << firstent(T, P);
}
int* prefix(string s)
{
    int*p = new int[s.length()];
    int k = 0;
    p[0] = 0;
	for (int i = 1; i < s.length(); i++)
	{
		while (k > 0 && s[k] != s[i])
		{
			k = p[k - 1];
		}
		if (s[k] == s[i])
		{
			k++;
		}
		p[i] = k;
	}
	    return p;
}
int firstent(string str, string P) {
	int m = P.length();
	if (m == 0)
	{
		return 0;
	}
	int* p = prefix(P);
	for (int i = 0, k = 0; i < str.length(); i++)
		while (true)
		{
			if (P[k] == str[i])
			{
				k++;
				if (k == m)
				{
					return i + 1 - m;
				}
				break;
			}
			if (k == 0)
			{
				break;
			}
			k = p[k - 1];
		}
	return -1;
}